In modern medicine, methods associated with use of ultrasonic fields have found application in surgical practice, diagnostic investigations, therapeutic procedures.
With the assistance of ultrasound, liquids and surgical instruments are sterilised, high-dispersion forms of medicinal preparations are prepared.
Depending upon characteristics of ultrasonic fields, the last-mentioned can cause a wide diversity of physical effects in systems subjected to processing, exactly, mechanical destruction, dispersion, emulsification, cavitation, thermal heating, excitation of intrinsic oscillations, etc. (Ultrazvuk. Malenkaya Entsiklopedia (Ultrasound. Small Encyclopaedia)./Ed. by I.P. Golyamina. Moscow: Sovetskaya entsiklopedia (Soviet Encyclopaedia Publishers). 1979.-399 pp.).
When ultrasonic fields having different characteristics act to biological tissues, complexes of active physics factors can imply an antiphlogistic, anaesthetic, disinfecting, stimulating action.
To treat urolithiasis, for example, it has been proposed to act to the region of the projection of kidneys with opposite phase ultrasonic fields simultaneously from back and abdomen in the plane of location of a kidney, said fields having a frequency of from 1 to 5 kHz and an intensity of from 2 to 5 mW/cm2, wherein selection of the frequency and intensity is carried out according to subjective perceptions of a patient.
The opposite phase operation of radiation sources provides not merely increase of an intensity of oscillations but achievement of its more uniform distribution in a patient's body in the travelling wave mode with the constancy of an intensity of action within a resonator formed by the patient's body (RF Patent 2,099,040, A 61 H 23/00, 1997).
The prior art method for treatment of children having chronic pyelonephritis comprises the step of acting to the region of kidneys, adrenal glands and urhetrae with a ultrasonic field having a frequency of 880 kHz at an intensity of from 0.05 to 0.2 W/cm2, the intensity and duration of action being increased depending upon the severity of a disease.
In such modes of action with ultrasonic fields, the stabilising effect is achieved relative to cell membranes of kidneys, that allows to reduce treatment periods and to decrease the number of exacerbations (USSR Inventor's Certificate 1,456,153, A 61 H 23/00, 1989).
To prevent the second-order reactions of regional hemodynamics when the vibration massage is carried out, there are the steps of preliminary determining the second harmonic of an intrinsic frequency of a patient's cardiovascular system on the basis of rheographic data obtained after applying a series of actions with frequencies of from 16 to 32 Hz with a step of 2 Hz, an amplitude of 4 mm, a duration of 2 minutes from an extremity by a peak of an average velocity of the maximum pulse volume, and effecting a vibration action at said frequency (USSR Inventor's Certificate 1,163,853, A 61 H 23/00, 1985).
When mechanical vibration actions are effected for stimulating the muscles of sportsmen, there are the steps of preliminary measuring a frequency and an amplitude of mechanical oscillations generated by tensioned muscles, and effecting a vibration action at a frequency being a multiple of the measured frequency, and with an amplitude being equal to the measured amplitude (USSR Inventor's Certificate 1,174,026, A 61 H 23/00, 1985).
Disclosure has been made of a device for ultrasonic therapy, whose function basis was the principle of synchronising a ultrasonic action with a frequency, an amplitude and a duration of a determined biological parameter, for example, a blood volume of a body section to be irradiated. In doing so, information about some biological parameter, for example a frequency, an amplitude and a duration of pulse oscillations, is converted into an electrical signal that, after amplification and filtration, guides the operation of the generator.
Such a constant biocontrol and bioregulation by ultrasonic fields allows to individualise and optimise the character of action (USSR Inventor's Certificate 562,279, A 61 H 23/00, 1977).
The similar method of action of ultrasonic fields to animal organisms comprises the steps of fixing a primary information sensor (for example, a piezoelectric sensor) at a body of an animal, which sensor controls the operation of a ultrasonic oscillation generator. As a primary information it is possible to use, for example, information about a pulse rate. An electrical signal in the form of a sine-like curve obtained from the primary information sensor is supplied as a control signal to the ultrasonic oscillation generator.
Thus, the action with a ultrasonic field is effected at a periodicity equal to a contraction frequency of the cardiovascular system of an organism, that reduces the energy supply to the organism because tissues, especially a nervous tissue, are more responsive to intermittent irritations than to continuous irritations (USSR Inventor's Certificate 649,429, A 61 H 23/00, 1979).
It has been patented a ultrasonic therapeutic apparatus whose design aspects allow to create a stochastic and wideband ultrasonic field, that has certain advantages: the action of said fields does not cause the habituation and reduces the second-order actions to tissues surrounding an affection nidus, because the acoustic energy is distributed in a wide frequency range.
This apparatus includes a ultrasonic oscillation source comprising a signal frequency and phase variator, a power amplifier comprising an amplitude normaliser, wherein the power amplifier is connected to a wideband ultrasonic radiator in the form of a multimode cavity resonator, said radiator being polarised according to a linear law (RF Patent 2,066,215, A 61 H 7/00, 1996).
As the effectiveness of action of ultrasonic fields to an organism is determined by parameters of a used ultrasonic field and modes of action, then, selection of said parameters is of critical importance.
In all the above-mentioned techniques of action of ultrasonic fields to an organism, the parameters of an active field were determined empirically or were based on values defining the activity of a patient's cardiovascular or muscular system.
However, the selection of active ultrasonic field parameters according to said criteria has no clear biophysical basis, and there is no any assurance that such parameters are optimal.